Michael Herr, seen in this Sept. 1,1997 photo, wrote about the Vietnam War and contributed to the screenplays of “Apocalypse Now” and “Full Metal Jacket.” (Dudley Reed/Contour by Getty Images)

Michael Herr, a Vietnam War reporter whose “Dispatches” remains one of the most powerful books about the ravages of combat and who later contributed to the screenplays of such bleak Vietnam-set films as “Apocalypse Now” and “Full Metal Jacket,” died June 23 near his home in Upstate New York. He was 76.

His daughter Claudia Herr confirmed the death but declined to provide further details. He lived in Delhi, N.Y.

“Dispatches,” published in 1977, drew resounding critical praise. It was one of the first books to confront the Vietnam War in all its hallucinogenic awfulness and jarring absurdities. It was instantly placed in the pantheon of great war literature, widely viewed as journalism alchemized seamlessly into art.

The spy novelist John le Carré called “Dispatches” “the best book I have ever read on men and war in our time.” New York Times book critic John Leonard hailed Mr. Herr’s work as “beyond politics, beyond rhetoric, beyond ‘pacification’ and body counts and the ‘psychotic vaudeville’ of Saigon press briefings. . . . It is as if Dante had gone to hell with a cassette recording of Jimi Hendrix and a pocketful of pills: our first rock-and-roll war, stoned murder.”

Part autobiography, part journalism but largely fiction, the book is an impressionistic tour de force of Mr. Herr’s two years in Vietnam reporting for Esquire magazine at the height of the war. Shunning conventional reportage, the “nonfiction memoir,” as it was sometimes called, illuminated the mundane and the terrifying, as well as how service members — and fellow journalists — endured their years in a hell zone.

The book arrived two years after the U.S. withdrawal from Southeast Asia following more than a decade of war that cost more than 58,000 American lives and countless casualties among the Vietnamese, Cambodians, Laotians and others. “Dispatches” arrived as a shockingly visceral remembrance of a war that many wanted to forget.

“You know how it is, you want to look and you don’t want to look,” Mr. Herr wrote about the sight of dead bodies. “Once, I looked at them strung from the perimeter to the treeline, most of them clumped together nearest the wire, then in smaller numbers but tighter groups midway. . . . Then I heard an M16 on full automatic, starting to go through clips, a second to fire, three to plug in a fresh clip, and I saw a man out there, doing it. Every round was like a tiny concentration of high-velocity wind, making the bodies wince and shiver.”

In other passages, he evoked extreme survival measures: an American soldier who blanketed himself with the corpses of his comrades to avoid being bayoneted by enemy forces that had overrun them; or the American troops on a packed helicopter compelled to shoot Vietnamese allies who swarmed them and threatened to prevent the chopper’s take-off amid hostile fire.

Like few other writers, Mr. Herr captured chaos with intense precision and imagination. He based his work on all he had seen but liberated himself from journalistic fact. His book was a fever dream of conversation, blood, drugs and rock music. Shortly before leaving Vietnam, his photographer friend Sean Flynn, who later disappeared and was presumed dead, told him not to squander all he had seen on cocktail talk back in Manhattan.

Instead, he spent 18 months consumed by “Dispatches,” writing the bulk of it before spiraling into a breakdown. “Real despair for three or four years,” he told the London Observer. “Deep paralysis. I split up with my wife for a year. I didn’t see anybody because I didn’t want anybody to see me.”

He only gradually emerged, completing a book he knew would resonate and catapult him to renown. Indeed, he was an instant celebrity, bombarded with interview requests and invitations to Hollywood soirees. He bristled at the fame, the random calls at night, the oddball requests from strangers who thought they owned a piece of him. He began a long and concerted effort to get off the radar.

He moved to England in search of a quiet life. One offer beckoned that he could not refuse: He wrote the trance-like narration (voiced by Martin Sheen) in filmmaker Francis Ford Coppola’s epic about war and madness, “Apocalypse Now” (1979). He also co-scripted Stanley Kubrick’s “Full Metal Jacket” (1987) and later wrote a book about Kubrick.

He wrote a screenplay about the powerful 1930s and 1940s gossip columnist Walter Winchell, whose rise, he told the Los Angeles Times, augured “a kind of promiscuous attention to all kinds of business not properly our business, a horrible dominance of entertainment in American life.”

The producers balked at his thesis, and Mr. Herr turned the script into a novel, published to good reviews in 1990. But mostly, when he consented to interviews, the focus was squarely on his first book, a masterpiece that exhumed what he called “the death space and the life you found inside it.”

Michael David Herr was born in Lexington, Ky., on April 13, 1940, and grew up in Syracuse, N.Y., where his father worked as a jeweler. The younger Herr described himself as a “nice, middle-class, educated Jewish boy who as a kid had every nervous tic and allergy possible.”

He recalled that as a pre-teen, feeling stifled and confined, he sometimes followed strangers around town by bus and foot because he “just wanted to see where and how they lived.”

He entered Syracuse University and wrote for the college literary magazine, which was edited by Joyce Carol Oates, but he dropped out, driven by a wanderlust he attributed to his idolization of Ernest Hemingway and other authors who drank and smoked their way across the globe.

After a year roaming Europe, he was hired as a film critic for the leftist New Leader magazine but was soon fired for what he called “liking all the wrong movies.”

There was a stint as an Army reservist and as a travel writer for Holiday magazine. He struck up a friendship with Esquire magazine editor Harold Hayes and proposed a monthly column from Vietnam. He was able to get helicopter rides to far reaches of the combat zone, but he was not a highly productive correspondent. Little of his writing made it into print.

Most of the time, he told the Times, he was “just going off on long operations, coming back six weeks later and going into my room and smoking a ton of dope and writing notes.” He interviewed troops in the field and even participated in operations against the Viet Cong when the grunts he was accompanying came under attack in the Mekong Delta.

“I can remember four o’clock patrols where I was allowed to go only if I carried a weapon, so I carried a weapon,” he later told the Boston Globe. “I only had to use a weapon twice. And I had to, I had to. It was impossible not to.”

Survivors include his wife, Valerie Elliott, whom he married in 1977; their daughters Claudia Herr and Catherine Herr; a brother; and a sister.

He returned to the United States in 1990 and relished his anonymity. He found it grotesque when TV producers rang up with lucrative offers to revisit Vietnam on camera.

“I do believe it’s OK to have been there — to have seen it, to have participated in it,” he told the Globe. “I wish people didn’t have to suffer for 20 years for what happened there. Just in the way that I wish that all the people who remember it would forget it, I wish all the people who’ve forgotten it would remember it — if they could just change places. And all those guys could move that rock off their chests.

“I don’t know if there’s any other level on which catharsis is possible — other than doing it alone, and quietly.”